1. Field of the Invention
This invention relates in general to nano technology and, more specifically, to technology for producing coatings reinforced with alumina Al2O3 nanofibers.
2. Description of the Related Art
Nanotechnology deals with developing materials, devices, or other structures having at least one dimension sized between 1 and 100 nanometers. Nanoparticles are the particles having at least one dimension sized between 1 and 100 nanometers. On the other hand, nanofibers are defined as fibers with diameters less than 1000 nanometers. Nanofibers are widely used for manufacturing coatings (nanocoatings) having enhanced properties, such as coatings consisting of polymers reinforced by nanoparticles.
At the present time, several kinds of nanoparticles which can be used in the production of nanocoatings are known in the art, including, without limitation, carbon nano tubes (CNT), nano powders produced from silicon carbide, alumina and other materials. Also known in the art are various methods for nanoparticle or nanofiber fabrication, including, without limitation: hydrothermal process, sol gel process, mercury mediated process, flame-spray method, vapor-liquid-solid process as well as electrospinning method.
However, the conventional methods for fabrication of nanoparticles for use in nanocoatings suffer from low production output and, consequently, are expensive and time consuming. For example, a system for enabling a typical electrospinning nanofiber fabrication process consists of three major components: a high-voltage power supply, a spinneret, and an electrically conductive collector. A liquid used in the aforesaid electrospinning technique is fed at a predetermined rate using a syringe or other suitable pump. In many cases, a well-controlled environment (e.g., humidity, temperature, and atmosphere) is critical to the operation of electrospinning, especially for the fabrication of ceramic nanofibers. As would be appreciated by those of skill in the art, these features make the electrospinning process rather expensive as well as resource and time-consuming. The other conventional nanofiber fabrication methods suffer from similar drawbacks and production bottlenecks, which reduce their throughput. In addition, the conventional nanofiber fabrication techniques such as the aforesaid electrospinning process are not suitable for manufacturing metal oxide nanofibers.
In addition, conventional techniques for producing thin film coatings are also deficient. Widely used in semiconductor manufacturing process is a plasma deposition method, wherein the material to be deposited on the substrate is heated to a very high temperature in a plasma chamber resulting in deposition of atoms of the heated material onto the surface. However, the high temperatures needed for plasma deposition may damage the substrate. In addition, the plasma deposition method is energy consuming, slow and expensive.
Thus, new techniques for producing coating materials and applying them to the substrates are needed.